SSH:Permission denied on first boot on Rpi 2

Hi. I just installed OMV in my Raspberry Pi 2, but when I boot it up, I have no video output. When trying to open the web UI, a ERR_CONNECTION_REFUSED error is shown. I'm also trying to connect via ssh to run omv-firstaid (nmap shows that the device is up and has the ssh port open), but the default password on the readme for root (openmediavault) just renders a "Permission denied, please try again." error. What am I missing here?

I tried both OMV 3.0.13 Beta and OMV 2.2.1, and also tried with different microSD cards.

Well, I have just figured it out. At first I noticed that the ACT led was not flashing, so my first guess was a corrupted sd, but....two? So I kept checking them on my pc and rewriting different distros (using disk utility in elementary OS). They seemed fine, so I started to get scared of a dead raspi. The contacts on the sd tray seemed OK to me, and the multimeter showed almost constant 5V.

I rebooted my PC to the Windows partition and rewrote the image using Win32DiskImager. Now the raspi started booting up, but the PWR led flashed in a strange manner, and if I moved the cable the pi would power off. At last, I changed my power supply and now everything is OK. So, in the end, it seems like it was a not correctly written card and a faulty power supply. Now I just wonder what's the matter with disk utility, since I've used it hundreds of times.